Deformation behaviour of granular column reinforced by geosynthetic encasement

Abstract

In Vietnam, the overpopulation and strong economic development require the synchronous development of infrastructure such as roads, urban areas, industrial parks, export processing zones, etc. With such requirements, the development of land fund for infrastructure construction is an indispensable need. Meanwhile, the appropriate land fund is very limited. Therefore, the land fund must be developed for areas with little value for agriculture, such as swamps, estuaries, and coastal areas, etc. These areas often have weak geological conditions; hence, to meet the requirements of infrastructure construction on the soft ground, it is necessary to carry out soil improvement to ensure load bearing capacity, total settlement, and consolidation settlement but still ensuring economic effectiveness. Beside several conventional methods widely used for soft soil improvement in order to increase bearing capacity and accelerate consolidation settlement of the ground, geosynthetic reinforced granular column is one of the new methods that has been applied to improving soft ground in designing practice in the recent years due to the many advantages of this method compared with other methods. In this paper, based on the unit cell model, the authors research on deformation behavior of granular column reinforced by geosynthetic encasement through the analytical analysis by varying external loadings corresponding to column diameter, stiffness of geosynthetic encasement. The settlements of a single geosynthetic encased granular column and load bearing capacity of the composite foundation are calculated on geological conditions of Ash Pond Area of Song Hau 1 Thermal Power Plant located in Hau Giang Province. The relationship between settlement and load bearing capacity with external loadings for different column diameters and geosynthetic stiffnesses are shown schematically. Other considerations related to factor of safety are also presented. The future researches are also proposed.